This section provides background information related to the present disclosure, which is not necessarily prior art.
Undesirable fluidic noises and vibration can occur in a refrigerant line or a fluid line during phase change of the contents thereof, such as, for example, steering fluid, brake fluid, or fuel. To suppress these noises, a damper can be applied to the line. The damper often takes the form of high density tape wrapped around the fluid line or a heavy mass damper. For example, mastic tape is often used as a damping layer, but this petroleum based product can be difficult to work with and may become damaged at high temperatures. With respect to mass dampers, they undesirably add weight to the line and any vehicle that may include the line.
With respect to HVAC systems for example, most of the noises and vibration induced by the A/C compressor and the heater-core propagate from the inlet/outlet pipes associated with the evaporator and heater-core respectively. Increasing the length of the hoses attached to the inlet/outlet pipes attenuates the noise propagation to a certain extent. However, due to added weight, stiffness, and the unattractive appearance of the hoses, costly mufflers are sometimes used. Alternatively, unattractive viscous, mastic material is sometimes applied to tubes of standard length, which can also be costly and of limited effectiveness.
An example of an undesirable HVAC sound is the hissing and gurgling noise induced following air conditioning cycling. Its source is usually the sudden release and expansion of refrigerant at high pressure though the thermal expansion valve (TXV). This noise is often amplified through the grounding between the evaporator and the HVAC case. Furthermore, the noise transmits from inlet to outlet by way of the evaporator. To dampen this noise, the evaporator and tubes between the evaporator and the TXV are often wrapped with mastic material, which is costly and of limited effectiveness. Dampers can also be used to suppress compressor induced tones and/or growls propagating through air conditioner lines.